That led to a long period where startups were shipping things that barely worked and would fall apart if you deviated from the happy path at all.
Companies and consumers alike got tired of paying to be alpha testers and do market research for startups. It was really bad when you’d start using a startup product, spend a lot of time working with them to identify bugs, and then they would pivot to some other idea they had.
Nope. They did, but that's not the problem.
The problem is that VCs moved way too much in the direction of "take over the world or go home" and don't allow companies that take investment to be just successful anymore.
In many cases, the problem can only be understood through many failed solution attempts. It could be because the actual problem is novel. It could be because there is a different way of thinking about the problem that is not apparent studying only what a customer does today with the limitations of the software that they have right now.
The point of "move fast, break things" is to address this fallacy that anyone can fully understand a problem before attempting the solution; it is often the case that in attempting a solution, one comes to understand the actual, valuable problem.